Sunflower Q & A
1. Are Sunflowers Annuals, Biennials, or Perennials?
It depends on the variety you are using. Many plants are commonly referred to as sunflowers. The botanical name for Common or Annual Sunflower is Helianthus annuus. There are many varieties from large 1 ft and larger flowers heads used for seed production to smaller headed beauties useful for cut flowers. These plants do tend to self seed so people often think of them as a perennial. However, the main plant will die after a frost. If you allow the seed heads to stay in place over winter, they will often sprout new plants from the dropped seeds the next year.
Heliopsis helianthoides is the botanical name often associated with perennial sunflowers. These look like mini sunflowers. They are a perennial flower returning year after year in Wisconsin. Make sure this is the look you are going for before planting though since they are more similar looking to Black Eyed Susans or Yellow Coneflowers in size than the traditional annual Sunflower.
2. How late can I plant Sunflowers seeds and still get blooms?
The time it takes from seed planting to bloom depends on the variety. Here in Wisconsin, annual Sunflowers are one of the quickest to bloom after planting. Some varieties can bloom as soon as 50 days from planting. If you are using seeds that have come in a seed packet, make sure to reference the maturity time from planting to flowering. When in doubt, keep in mind the range for most annual Sunflowers is 50- 85 days. Since first frost dates vary through southern Wisconsin, it is best to plant the last of the sunflower seeds by the beginning of August.
3. Where is the best spot to plant sunflowers?
As the name says, these flowers like the sun! Plant sunflowers in well drained soil with at least 6-8 hours of sun. They are not particularly picky though, since they can often be seen growing happily under bird feeders and in other places where the seeds drop.
4. Can I save the seeds from my sunflowers?
Yes, you can! Your intended purpose will determine your next step. One easy option is to leave them in place to dry outside for the birds. The birds will eat off the plant through the fall, winter, and spring (if there are any left). Some seeds often drop and self sow when the conditions are right the following late spring or early summer. You can also cut the plants and put the whole head into a paper bag to dry. The seeds can be plucked off and saved for later.
5. How big do sunflower plants get?
There are tons of different varieties ranging from 1 ft tall to over 15 ft tall. The taller varieties are typically the ones that are good for large seed heads. Large seed heads are great for wowing the kids and/or feeding the birds. Generally, a midrange type is best for cut flowers. Some of my favorites for cut flowers are from the ProCut ® series. ProCut ® are single stem varieties with a height of 5-6 ft and come in a multitude of colors with a pollenless flower size of about 4-6 inches.
